Lens driving device, camera device, and electronic apparatus

ABSTRACT

A lens driving device includes a lens support, a first moving member plate and a second moving member plate that surround around a periphery of the lens support, wherein the first moving, member plate is supported so as to be freely movable relative to the second moving member plate by a first support mechanism that includes a first support protrusion and a first guide recess into which the first support protrusion is fitted, the lens support is supported so as to be freely movable relative to the first moving member plate by a second support mechanism that includes a second support protrusion and a second guide recess into which the second support protrusion is fitted.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 16/151,386, filed on Oct. 4, 2018, entitled “LENS DRIVINGDEVICE, CAMERA DEVICE, AND ELECTRONIC APPARATUS”, which is incorporatedherein by reference in its entirety.

TECHNICAL FIELD

The present invention relates to a lens driving device, a camera device,and an electronic apparatus.

BACKGROUND ART

A small-sized camera is mounted on an electronic apparatus, e.g., amobile phone or a smart phone. As this type of small-sized camera, forexample, as disclosed in US 2015/049209, there is known a small-sizedcamera having an image stabilization function.

SUMMARY

In US 2015/049209, the camera includes a lens support configured tosupport a lens, and a frame member surrounding a periphery of the lenssupport. In order to support the lens support so as to be freely movablein a direction orthogonal to an optical axis direction of the lensrelative to the frame member, a plurality of balls are used. Further,the related-art lens driving device includes a magnet and a magneticmember provided so as to be opposed to the magnet. An attraction forcegenerated between the magnet and the magnetic member causes the balls tobe sandwiched between the lens support and the frame member.

However when a force larger than the attraction force between the magnetand the magnetic member is applied due to, for example, falling, thelens support may be separated from the balls, and then the lens supportmay hit the balls again. The frame member that is brought into pointcontact with the balls receives the impact, and thus there have beenproblems in that a dent or a crack may occur in a ball hitting part andsmooth movement of the lens support may not be ensured.

The present invention has been nude to solve the above-mentionedproblems in the related art, and has an object to provide a lens drivingdevice, a camera device, and an electronic apparatus, which are capableof ensuring smooth movement of a lens support.

In one aspect of the prevent invention is a lens driving device. Thelens driving device includes: a lens support configured to support alens; a first moving member plate and a second moving member plate thatsurround around a periphery of the lens support, wherein the firstmoving member plate is supported so as to be freely movable relative tothe second moving member plate by a first support mechanism thatincludes a first support protrusion and a first guide recess into whichthe first support protrusion is fitted, the lens support is supported soas to be freely movable relative to the first moving member plate by asecond support mechanism that includes a second support protrusion and asecond guide recess into which the second support protrusion is fitted,no guide recesses are formed on the first moving member plate while boththe first support protrusion of the first support mechanism and thesecond support protrusion of the second support mechanism are formed onthe first moving member plate so that the first support protrusionprotrudes from the first moving member plate towards one side of anoptical axis direction of the lens and that the second supportprotrusion protrudes from the first moving member plate towards anotherside of the optical axis direction, the first guide recess of the firstsupport mechanism is formed on the second moving member plate so as tobe recessed toward the one side of the optical axis direction, and thefirst guide recess has two side surfaces expanding along the opticalaxis direction so as to oppose to each other, and a bottom surface thatconnects the two side surfaces, the second guide recess of the secondsupport mechanism is formed on the lens support so as to be recessedtoward another side of the optical axis direction, and the second guiderecess has two side surfaces expanding along the optical axis directionso as to oppose to each other, and an upper surface that connects thetwo side surfaces.

Preferably, the first support protrusion and the first guide recess arein contact each other at an ends thereof in the optical axis direction,and the second support protrusion and the second guide recess are incontact each other at an ends thereof in the optical axis direction.

Preferably, the first moving member plate and the second moving memberplate are in contact only at the first support protrusion and the firstguide recess.

Preferably, the lens support and the first moving member plate are incontact only at the second support protrusion and the second guiderecess.

Preferably, the lens support is provided with a magnet that generates adriving force for movement, the second moving member plate is providedwith a magnetic member so as to generate an attraction force between themagnet and the magnetic member along the optical axis direction throughintermediation of the second moving member plate.

Preferably, the second moving member plate has a rectangular bottomplate having four corners, a protrusion that protrudes toward theoptical axis direction is provided on each four corner of therectangular bottom plate, a cover is fixed to a distal end of theprotrusion, and a gap is formed between the cover and the lens supportin the optical axis direction.

Preferably, the first support mechanism and the second support mechanismare provided on each corner of rectangular outer profiles of the lenssupport, the first moving member plate, and the second moving memberplate when viewing from the optical axis direction, and the firstsupport mechanism and the second support mechanism are overlaid eachother at each corner of the rectangular outer profiles.

Preferably, the first support protrusion is in contact with the two sidesurfaces and the bottom surface of the first guide recess, and thesecond support protrusion is in contact with the side surfaces of theupper surface of the second guide recess.

Another aspect of the present invention is a camera device. The cameradevice includes: the lens driving device of the above aspects; and alens supported by the lens support.

Another aspect of the present invention is an electronic apparatus. Theelectronic apparatus includes the camera device of the above aspect.

According to the present invention, the first and the second supportprotrusion and the first and the second guide recess extend in thedirection orthogonal to the optical axis direction of the lens, and thefirst and the second support protrusion are in contact with the firstand the second guide recess respectively at least at two points in thecross section in the optical axis direction of the lens. Therefore, thelens support or the frame member receives less impact in the opticalaxis direction of the lens, and the smooth movement of the lens supportcan be ensured.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view for illustrating a camera deviceaccording to a first embodiment of the present invention as viewedobliquely from above.

FIG. 2 is an exploded perspective view for illustrating a moving memberused in the camera device according to the first embodiment of thepresent invention as viewed obliquely from above.

FIG. 3 is an exploded perspective view for illustrating the movingmember used in the camera device according to the first embodiment ofthe present invention as viewed obliquely from below.

FIG. 4 is an exploded perspective view for illustrating a part of afixed member used in the camera device according to the first embodimentof the present invention as viewed obliquely from above.

FIG. 5 is a perspective view for illustrating a flexible printed boardused in the camera device according to the first embodiment of thepresent invention.

FIG. 6 is an X-direction sectional view for illustrating the movingmember used in the camera device according to the first embodiment ofthe present invention.

FIG. 7 is a Y-direction sectional view for illustrating the movingmember used in the camera device according to the first embodiment ofthe present invention.

FIG. 8 is a sectional view for illustrating the camera device accordingto the first embodiment of the present invention.

FIG. 9 is a sectional view for illustrating the camera device accordingto the first embodiment of the present invention, which is taken alongthe line A-A of FIG. 8.

FIG. 10 is a sectional view for illustrating the camera device accordingto the first embodiment of the present invention, which is taken alongthe line B-B of FIG. 8.

FIG. 11 is a sectional view for illustrating a periphery of a firstsupport mechanism in a camera device according to a second embodiment ofthe present invention.

FIG. 12 is a sectional view for illustrating a periphery of a secondsupport mechanism in the camera device according to the secondembodiment of the present invention.

FIG. 13 is a sectional view for illustrating a periphery of a firstsupport mechanism in a camera device according to a third embodiment ofthe present invention.

FIG. 14 is a sectional view for illustrating a periphery of a secondsupport mechanism in the camera device according to the third embodimentof the present invention.

FIG. 15 is an XY-direction sectional view for illustrating a firstsupport mechanism in a camera device according to a fourth embodiment ofthe present invention.

FIG. 16 is an XY-direction sectional view for illustrating a firstsupport mechanism in a camera device according to a fifth embodiment ofthe present invention.

EXEMPLARY EMBODIMENT OF THE PRESENT INVENTION

Embodiments of the present invention are described with reference to thedrawings.

FIG. 1 to FIG. 10 are illustrations of a first embodiment of the presentinvention.

FIG. 1 is an illustration of a camera device 10 according to the firstembodiment of the present invention. The camera device 10 includes alens driving device 12 and a lens 14 mounted to the lens driving device12.

The lens driving device 12 includes a fixed member 16 and a movingmember 18 supported so as to be freely movable relative to the fixedmember 16. As illustrated in FIG. 2 and FIG. 3, the moving member 18includes a lens support 20 and a first frame member 22 surrounding thelens support 20. The lens support 20 and the first frame member 22 eachhave a substantially quadrangular outer shape as viewed from above.

For the sake of convenience, an optical axis direction of the lens 14 isherein referred to as “Z direction”, a direction orthogonal to theoptical axis direction is referred to as “X direction”, and a directionorthogonal to the Z direction and the X direction is referred to as “Ydirection”. Further, an object side of an optical axis is referred to as“upper side”, and a side which is opposite to the upper side and onwhich an image sensor (not shown) is to be arranged is referred to as“lower side”.

The lens support 20 has a lens mounting hole 24. The lens mounting hole24 has a circular shape as viewed from the direction and is formed onthe inner side of the lens support 20. The lens 14 is mounted to thelens mounting hole 24.

The first frame member 22 includes a first moving member plate 26, asecond moving member plate 28, and a first cover 30. The lens support20, the first moving member plate 26, and the second moving member plate28 are each made of engineering plastics such as liquid crystal polymer(LCP), polyacetal, polyamide, polycarbonate, modified polyphenyleneether, and polybutylene terephthalate. Further, the first cover 30 ismade of, for example, a metal. The first moving member plate 26, thesecond moving member plate 28, and the first cover 30 have openings 32,34, and 36, respectively, for allowing passage of light therethrough.The openings 32, 34, 36 are each formed in a substantially circularshape.

The first frame member 22 supports the lens support 20 so as to befreely movable in the Y direction and the X direction. That is, thefirst frame member 22 includes an orthogonal-direction support mechanism38, and is configured so that the lens support 20 is freely movable inXY directions via the orthogonal-direction support mechanism 38.

The orthogonal-direction support mechanism 38 includes a first supportmechanism 40 and a second support mechanism 42 that are provided awayfrom each other in the Z direction. The first support mechanism 40 isprovided on the lower side in the Z direction, and as illustrated inFIG. 6 and FIG. 7, includes a first support portion 44 formed so as toprotrude on a lower surface of the first moving member plate 26 and afirst guiding portion 46 formed so as to be recessed in an upper surfaceof the second moving member plate 28. The first support portion 44 isfitted to the first guiding portion 46. The first support portion 44 andthe first guiding portion 46 extend in the X direction, and are formedin the vicinity of each of four corner portions of the first movingmember plate 26 and the second moving member plate 28. The first supportportion 44 and the first guiding portion 46 extending in the X directionare fitted to each other so as to regulate movement in the Y direction,and hence the first moving member plate 26 is freely movable only in theX direction relative to the second moving member plate 28. The firstsupport portion 44 and the first guiding portion 46 are surrounded bythree orthogonal lines in a cross section (see FIG. 7) taken along the Zdirection in the Y direction, and are brought into surface contact witheach other in three planes (opposed side surfaces and lower surface) inthe X direction.

The second support mechanism 42 is provided on the upper side in the Zdirection, and as illustrated in FIG. 6 and FIG. 7, includes a secondsupport portion 48 formed so as to protrude on an upper surface of thefirst moving member plate 26 and a second guiding portion 50 formed soas to be recessed in a lower surface of the lens support 20. The secondsupport portion 48 is fitted to the second guiding portion 50. Thesecond support portion 48 and the second guiding portion 50 extend inthe Y direction, and are formed in the vicinity of each of four cornerportions of the lens support 20 and the first moving member plate 26.The second support portion 48 and the second guiding portion 50extending in the Y direction are fitted to each other so as to regulatemovement in the X direction, and hence the lens support 20 is freelymovable only in the Y direction relative to the first moving memberplate 26. The second support portion 48 and the second guiding portion50 ate surrounded by three orthogonal lines in a cross section (see FIG.6) taken along the Z direction in the X direction, and are brought intosurface contact with each other in three planes (opposed side surfacesand upper surface) in the X direction.

At each of four corners of the first cover 30, a mounting portion 52 isprovided so as to extend downward in the Z direction. The mountingportion 52 has a quadrangular mounting hole 54. Further, at each of fourcorners of the second moving member plate 28, a mounted portion 56 isformed so as to laterally protrude. The mounted portion 56 is fitted tothe mounting hole 54, so that the first cover 30 is fixed to the secondmoving member plate 28. Between a lower surface of the first cover 30and the upper surface of the lens support 20, as illustrated in FIG. 6and FIG. 7, there is ensured a necessity minimum gap including an errorcaused bye a tolerance or the like so as to regulate movement of thelens support 20 or the first moving member plate 26 in the Z directionrelative to the second moving member plate 28.

On the outer side of the lens support 20, first magnets 58 are fixed ontwo surfaces in the X direction and one surface in the Y direction. Eachof the first magnets 58 and 58 on the two surfaces in the X directionhas an S pole and an N pole formed in the X direction. Further, thefirst magnet 58 on the one surface in the Y direction has an S pole andan N pole formed in the direction.

Further, on two surfaces in the X direction in a lower surface of thesecond moving member plate 28, first magnetic members 60 and 60 made ofa magnetic substance are provided. The first magnetic members 60 and 60are opposed in the Z direction to the first magnets 58 and 58 on the twosurfaces in the X direction through intermediation of the second movingmember plate 28. An attraction force is generated between the firstmagnetic members 60 and 60 and the first magnets 58 and 58. Therefore,the lens support 20 and the first moving member plate 26 are attractedthrough intermediation of the second moving member plate 28, andZ-direction contact is maintained between the first support portion 44and the first guiding portion 46 and between the second support portion48 and the second guiding portion 50.

Further, on the second moving member plate 28, a second magnet 62 isfixed on an outer surface on the opposite side of the surface on whichthe first magnet 58 is provided in the Y direction. The second magnet 62is divided into two pieces in the Z direction. Each of the two pieceshas an S pole and an N pole formed in the Y direction, and oppositepolarities are provided in the vertical direction.

Next, a relationship between the fixed member 16 and the moving member18 is described.

Referring back to FIG. 1, the fixed member 16 includes a second framemember 64. The second frame member 64 surrounds the periphery of thefirst frame member 22 of the moving member 18. The second frame member64 includes a base 66 and a second cover 68. Each of the base 66 and thesecond cover 68 is made of a resin or a non-magnetic metal, and has asquare shape as viewed from above. The second cover 68 is fitted to theouter side of the base 66 to form the second frame member 64. Further,the base 66 and the second cover 68 have through holes 70 and 72,respectively, for allowing passage of light or insertion of the lens 14therethrough.

Further, as illustrated in FIG. 4, an opening portion 74 is formedthrough each of four side surfaces of the base 66. A flexible printedboard 76 is arranged so as to surround the outer side of the base 66 andsurround the opening portions 74. That is, as illustrated in FIG. 4 andFIG. 5, the flexible printed board 76 is bent into a quadrangular shapeso as to surround the outer shape of the base 66, and at a lower portionof the flexible printed board 76, a first terminal portion 78 and asecond terminal portion 80 are formed. The second terminal portion 80 isopposed to the first terminal portion 78 in the Y direction.Energization to a first coil 82 to be described later is controlled isthe first terminal portion 78, and energization to a second coil 84 tobe described later is controlled via the second terminal portion 80, butthe present invention is not limited thereto.

On the inner side of the flexible printed board 76, the first coils 82are fixed on two surfaces in the X direction and one surface in the Ydirection. Further, the second coil 84 is fixed on another surface inthe Y direction on the inner side of the flexible printed board 76.Further, on the inner side of the flexible printed board 76, anX-direction position detecting element 86 is arranged inside one firstcoil 82 in the X direction, a Y-direction position detecting element 88is arranged inside the first coil 82 in the Y direction, and aZ-direction position detecting element 90 is arranged on the lateralside of the second coil 84.

The first coils 82 and 82 provided on the two surfaces in the Xdirection are electrically connected to each other in series.

The first coils 82, the X-direction position detecting element 86, andthe Y-direction position detecting element 88 face the inner side of thebase 66 through the opening portions 74, and are opposed to the firstmagnets 58. Similarly, the second coil 84 and the Z-direction positiondetecting element 90 face the inner side of the base 66 through theopening portion 74, and are opposed to the second magnet 62.

Further, as illustrated in FIG. 1, on the outer side of the flexibleprinted board 76, a second magnetic member 92 made of a magneticsubstance is provided. The second magnetic member 92 is opposed to thesecond magnet 62 through intermediation of the flexible printed board 76and the second coil 84. Magnetic fluxes from the second magnet 62 flowthrough the second magnetic member 92 so that an attraction force isgenerated between the second magnet 62 and the second magnetic member92. Therefore, in the moving member 18, an attraction force acts in theY direction of the fixed member 16.

As illustrated in FIG. 1 and FIG. 8 to FIG. 10, the moving member 18 issupported by an optical axis-direction support mechanism 94 so as to befreely movable relative to the fixed member 16 in the Z direction. Theoptical axis-direction support mechanism 94 includes a third supportportion 96 and a fourth support portion 98 provided in the second framemember 64, and a third guiding portion 100 and a fourth guiding portion102 formed in the moving member 18. The third support portion 96 and thethird guiding portion 100 are combined with each other, and the fourthsupport portion 98 and the fourth guiding portion 102 are combined witheach other.

Each of the third support portion 96 and the fourth support portion 98is made of, for example, a ceramic, a metal, or a resin, and in thefirst embodiment, is formed as a column extending in the Z direction.Further, the third support portion 96 and the fourth support portion 98are provided away from each other in the X direction in the vicinity ofcorner portions of the base 20 on a side-surface inner side on thesecond magnet 62 side of the base 66.

Each of the third support portion 96 and the fourth support portion 98has a circular shape in an XY-direction cross section, but may have ashape of a part of a circle, or an oval or polygonal shape other thanthe circular shape.

That is, as illustrated in FIG. 1 and FIG. 8 to FIG. 10, a bottomsurface portion 104 is formed around the through hole 70 of the base 60,and lower fixing portions 106 and 106 are formed on both sides on theinner side of the bottom surface portion 104 as cylindrical grooves.Lower ends of the third support portion 96 and the fourth supportportion 98 are inserted and fixed to the lower fixing portions 106 and106. Further, upper ends of the above-mentioned second magnetic member92 at both ends in the X direction are bent in the Y direction to formupper fixing portions 108 and 108. Upper ends of the third supportportion 96 and the fourth support portion 98 are inserted and fixed toinsertion holes 110 and 110 formed in the upper fixing portions 108 and108 so that the third support portion 96 and the fourth support portion98 are fixed to the second frame member 64. In the first embodiment, thesecond magnetic member 92 also has a support function for the thirdsupport portion 96 and the fourth support portion 98, and thus thenumber of components can be reduced as compared to a case in whichcomponents for support are separately provided. Further, the thirdsupport portion 96 and the fourth support portion 98 can be stablysupported.

As illustrated in FIG. 8 and FIG. 9, the third guide portion 100includes a first contact portion 112 and a second contact portion 114formed away from each other in the Z direction. In the first embodiment,the first contact portion 112 and the second contact portion 114 areformed as circular holes, and are brought into contact with an outersurface of the third support portion 96 in a 360-degree circumferentialdirection in the XY-direction cross section of the third support portion96.

As illustrated in FIG. 8 and FIG. 10, in the XY-direction cross section,the fourth guide portion 102 is formed of two wall surfaces opposed toeach other in the Y direction. Both the wall surfaces of the fourthguide portion 102 protrude as a curve toward the fourth support portion98 to form protruding portions 116 and 116. Middles of the protrudingportions 116 and 116 correspond to a third contact portion 118 that isbrought into contact with the fourth support portion 98. The thirdcontact portion 118 is brought into contact with the fourth supportportion 98 at two points in the Y direction to reduce a frictionalresistance.

In the above-mentioned configuration, with energization to the firstcoils 82 and 82 opposed to the first magnets 58 and 58 on the twosurfaces in the X direction in which magnetic fluxes in the Z directionare interposed, currents flow through the first coils 82 and 82 in the Ydirection, and a Lorentz force acts on the first coils 82 and 82 in theX direction by the Fleming's left hand rule. The first coils 82 and 82are fixed to the base 66, and hence the lens support 20 and the firstmoving member plate 26 move in the X direction while being supported bythe first support mechanism 40 with a reaction force acting on the firstmagnets 58 and 58 serving as a drive force for the lens support 20 andthe first moving member plate 26.

In this case, as illustrated in FIG. 7, when the drive force in the Xdirection is represented by F_(x), the following expression may besatisfied to drive the lens support 20 and the second moving memberplate 28 in the X direction:

F _(x)>μ_(x1)(N _(x1) +W _(x1))+μ_(x2)(N _(x2) +W _(x2)).

In the expression, μ_(x1) and μ_(x2) each represent a frictioncoefficient between the first support portion 44 and the first guidingportion 46, W_(x1) and W_(x2) each represent a load to be applied to thefirst support portion 44, and N_(x1) and N_(x2) each represent a forceto be applied to the first support portion 44 due to the attractionforce between the first magnets 58 and 58 and the first magnetic members60 and 60. Further, the following expression may be satisfied:

N+W _(x)=(N _(x1) +W _(x1))+(N _(x2) −W _(x2)),

and F_(x) can be represented as follows:

F _(x)=μ_(x)(N+W _(x)),

provided that μ_(x) is an average value of μ_(x1) and μ_(x2).

Further, with energization to the first coil 82 opposed to the firstmagnet 58 in the Y direction in which magnetic fluxes in the Z directionare interposed, currents flow through the first coil 82 in the Xdirection, and a Lorentz force acts on the first coil 82 in the Ydirection by the Fleming's left hand rule. The first coil 82 it fixed tothe base 66, and hence the lens support 20 moves in the Y directionwhile being supported by the second support mechanism 42 with a reactionforce acting on the first magnet 58 serving as a drive force for thelens support 20.

In this case, as illustrated in FIG. 6, when the drive force in the Xdirection is represented by F_(y), the following expression may besatisfied to drive the lens support 20 in the Y direction:

F _(y)>μ_(y1)(N _(y1) +W _(y1))+μ_(y2)(N _(y2) +W _(y2)).

In the expression, μ_(y1) and μ_(y2) each represent a frictioncoefficient between the second support portion 48 and the second guidingportion 50, W_(y1) and W_(y2) each represent a load to be applied to thesecond support portion 48, and N_(y1) and N_(y2) each represent a forceto be applied to the second support portion 48 due to the attractionforce between the first magnets 58 and 58 and the first magnetic members60 and 60. Further, the following expression may be satisfied:

N+W _(y)=(N _(y1) +W _(y1))+(N _(y2) −W _(y2)),

and F_(y) can be represented as follows:

F _(y)=μ_(y)(N+W _(y)).

provided that μ_(y) an average value of μ_(y1) and μ_(y2).

When the energization to the first coil 82 is canceled after the lenssupport 20 is moved in any one of the X direction and the Y direction,the lens support 20 stops at a position at which the energization isslopped due to the attraction force between the first magnets 58 and 58and the first magnetic members 60 and 60, the friction between the firstsupport portion 44 and the first guiding portion 46, and the frictionbetween the second support portion 48 and the second guiding portion 50.

In this case, it is assumed that the camera device 10 receives, forexample, impact in a −Y direction. When the camera device 10 receivesthe impact in the −Y direction, the lens support 20 and the first movingmember plate 26 are caused to move in a +Y direction against theattraction force between the first magnets 58 and 58 and the firstmagnetic members 60 and 60. However, the lens support 20 and the firstmoving member plate 26 are not separated and hardly move even whenreceiving impact from the outride because the lens support 20 and thefirst moving member plate 26 are supported by the first supportmechanism 40 so as to regulate the movement in the Y direction. Afterreceiving the impact, the lens support 20 and the first moving memberplate 26 are applied with a force of returning the lens support 20 andthe first moving member plate 26 in the −Y direction due to theattraction force between the first magnets 58 and 58 and the firstmagnetic members 60 and 60. Also in this case, the lens support 20 andthe first moving member plate 26 hardly move even when receiving impactfrom the outside because the first support portion 44 and the firstguiding portion 46 maintain the contact. With respect to the impact inthe X direction, while the contact between the first support portion 44and the first guiding portion 46 is maintained, only the lens support 20is guided by the first support mechanism 40 to be moved relative to thefirst moving member plate 26. Further, also with respect to the impactin the Z direction, the contact between the first support portion 44 andthe first guiding portion 46 is easily maintained, but even when thefirst support portion 44 and the first guiding portion 46 are separatedfrom each other, the impact is received with a surface at the time ofreturn. Therefore, the damage is small, and smooth movement of the lenssupport 20 can be ensured. The second support mechanism 42 also actssimilarly.

Further, in the first support mechanism 40 and the second supportmechanism 42, the first support portion 44 and the first guiding portion46 are fitted to each other in the X direction, and the second supportportion 48 and the second guiding portion 50 are fitted to each other inthe Y direction, thereby forming independent support mechanisms.Therefore, a force in the rotation direction does not act even with asimultaneous drive in the XY directions, and the lens support 20 can beprevented from being vibrated in the rotation direction.

Next, with energization to the second coil 84 arranged between thesecond magnet 62 and the second magnetic member 92 in which magneticfluxes in the Y direction are interposed, currents flow through thesecond coil 84 in the X direction, and a Lorentz force acts on thesecond coil 84 in the Z direction by the Fleming's left hand rule. Thesecond coil 84 is fixed to the base 66, and hence the moving member 18moves in the Z direction while being supported by the opticalaxis-direction support mechanism 94 with a reaction force acting on thesecond magnet 62 serving as a drive force for the moving member 18.

In this case, when the drive force in the Z direction is represented byF_(x), the drive force F_(z) may satisfy the following expression todrive the moving member 18 in the Z direction:

F _(z)>(μ_(z3) ×N _(z3) +μ _(z4) ×N _(z4))+W.

In the expression, N_(z) represents an attraction force generated by thesecond magnet 62 (N_(z)=N_(z3)+N_(z4)), μ_(z3) represents a frictioncoefficient between the third support portion 96 and the third guidingportion 100, μ_(z4) represents a friction coefficient between the fourthsupport portion 98 and the fourth guiding portion 102, and W representsa total weight of the moving member 18.

When the energization to the second coil 84 is canceled after the movingmember 18 is moved in the Z direction, the moving member 18 stops at aposition at which the energization is stopped due to the attractionforce between the second magnet 62 and the second magnetic member 92,the friction between the thud support portion 96 and the third guidingportion 100, and the friction between the fourth support portion 98 andthe fourth guiding portion 102.

In this case, it is assumed that the camera dev ice 10 receives, forexample, impact in the −Y direction. When the camera device 10 receivesthe impact in the −Y direction, the moving member 18 is caused to movein the +Y direction against the attraction force between the secondmagnet 62 and the second magnetic member 92. However, the moving member18 hardly moves even when receiving impact from the outside becauseY-direction contact between the third guiding portion 100 and the thirdsupport portion 96 and between the fourth guiding portion 102 and thefourth support portion 98 is maintained. After receiving the impact, themoving member 18 is applied with a force of returning the moving member18 in the −Y direction due to the attraction force between the secondmagnet 62 and the second magnetic member 92. Also in this case, themoving member 18 hardly moves even when receiving impact from theoutside because Y-direction contact between the third guiding portion100 and the third support portion 96 and between the fourth guidingportion 102 and the fourth support portion 98 is maintained.

In this case, even when the third guiding portion 100 or the fourthguiding portion 102 is slightly deformed, the third support portion 96and the fourth support portion 98 have a shape extending in the Zdirection, and hence a force that is not local but successive acts alongthe Z direction on the third support portion 96 and the fourth supportportion 98. Therefore, abrupt motion change does not occur due to areciprocating motion of the moving member 18 or the like. Therefore, thesmooth movement of the lens support 20 can be ensured.

The moving member 18 is supported by the optical axis-direction supportmechanism 94 provided on the Y direction side, and further the movingmember 18 is heavy because the first magnets 58 and the like areprovided. Therefore, a moment of hanging downward in the Z direction isgenerated. However, the optical axis-direction support mechanism 94 issupported by the third support portion 96 and the fourth support portion98 extending in the Z direction, and hence as compared to a case inwhich balls are used for support as in the related art, theabove-mentioned hanging downward can be reduced.

FIG. 11 and FIG. 12 are illustrations of a second embodiment of thepresent invention.

As compared to the above-mentioned first embodiment, the secondembodiment differs in the structures of the first support mechanism 40and the second support mechanism 42.

That is, in the first support mechanism 40, the first support portion 44is formed so that its lower surface side protrudes in an arc shape.Therefore, in the Z-direction cross section illustrated in FIG. 11, sidesurfaces of the first support portion 44 and the first guiding portion46 are brought into line contact with each other, and bottom surfacesthereof are brought into point contact with each other. In the Xdirection, the side surfaces are brought into surface contact with eachother, and the bottom surfaces are brought into line contact with eachother. Further, the second support portion 48 is formed so that itsupper surface side protrudes in an arc shape. Therefore, in theZ-direction cross section illustrated in FIG. 12, side surfaces of thesecond support portion 48 and the second guiding portion 50 are broughtinto line contact with each other, and bottom surfaces thereof arebrought into point contact with each other. In the X direction, the sidesurfaces are brought into surface contact with each other, and thebottom surfaces are brought into line contact with each other.

As described above, in the first support mechanism 40 and the secondsupport mechanism 42, the first support portion 44 and the first guidingportion 46 are brought into surface or line contact with each other inthe X direction, and the second support portion 48 and the secondguiding portion 50 are brought into surface or line contact with eachother in the X direction. Therefore, the friction three can be reducedas compared to that in the first embodiment.

Parts similar to those in the first embodiment are denoted by the samereference symbols, and description thereof is omitted.

FIG. 13 and FIG. 14 are illustrations of a third embodiment of thepresent invention.

As compared to the above-mentioned first embodiment, the thirdembodiment differs in the structures of the first support mechanism 40and the second support mechanism 42.

That is, in the first support mechanism 40, the first support portion 44is formed so that its lower surface side protrudes in an arc shape,Therefore, in the Z-direction cross section illustrated in FIG. 13, sidesurfaces and bottoms surfaces of the first support portion 44 and thefirst guiding portion 46 are brought into point contact with each other.In the X direction, line contact is achieved at three points of the sidesurfaces and the bottom surface. Further, the second support portion 48is formed so that its upper surface and side surface sides protrude inan arc shape. Therefore, in the Z-direction cross section illustrated inFIG. 14, the side surfaces and the bottom surfaces of the second supportportion 48 and the second guiding portion 50 are brought into pointcontact with each other. In the X direction, line contact is achieved atthree points of the side surfaces and the bottom surface. In the thirdembodiment, in the Z-direction cross section, point contact is achievedin both side surfaces, but point contact may be achieved only in oneside surface.

As described above, in the first support mechanism 40 and the secondsupport mechanism 42, the first support portion 44 and the first guidingportion 46 are brought into contact with each other at three points inthe X direction, and the second support portion 48 and the secondguiding portion 50 are brought into contact with each other at threepoints in the X direction. Therefore, the friction force can be furtherreduced as compared to that in the second embodiment.

Parts similar to those in the first and second embodiments are denotedby the same reference symbols, and description thereof is omitted.

FIG. 15 is an illustration of a fourth embodiment of the presentinvention.

In the fourth embodiment, the first support portion 44 has a linear sidesurface, but the first guiding portion 46 has a shape of protruding in acurved shape. Therefore, the first support portion 44 and the firstguiding portion 46 are brought into point contact with each other in theXY-direction cross section.

FIG. 16 is an illustration of a fifth embodiment of the presentinvention.

In the fifth embodiment, the first guiding portion 46 has a linear sidesurface, but the first support portion 44 has a shape of protruding in acurved shape. Therefore, the first support portion 44 and the firstguiding portion 46 are brought into point contact with each other in theXY-direction cross section.

In the description above of the embodiments, a part formed into aprotruding shape is referred to as the support portion, and a partformed into a recessed shape is referred to as the guiding portion, butthe protruding part may be referred to as the guiding portion, and therecessed part may be referred to as the support portion. Further, theconfigurations of the first to fifth embodiments may be combined asappropriate.

The first magnet 58 and the first coil 82, and the second magnet 62 andthe second coil 84 may be arranged at interchanged positions. In thiscase, other members are optimally rearranged as appropriate. Further,the lens driving device 12 has a focus adjusting function and an imagestabilization function, but may further have a zoom function, forexample. The lens driving device 12 to be used in the camera device 10is described herein, but the present invention is also applicable toother devices.

1. A lens driving device, comprising: a lens support configured tosupport a lens; a first moving, member plate and a second moving memberplate that surround around a periphery of the lens support, wherein thefirst moving member plate is supported so as to be freely movablerelative to the second moving member plate by a first support mechanismthat includes a first support protrusion and a first guide recess intowhich the first support protrusion is fitted, the lens support issupported so as to be freely movable relative to the first moving memberplate by a second support mechanism that includes a second supportprotrusion and a second guide recess into which the second supportprotrusion is fitted, no guide recesses are formed on the first movingmember plate while both the first support protrusion of the firstsupport mechanism and the second support protrusion of the secondsupport mechanism are formed on the first moving member plate so thatthe first support protrusion protrudes horn the first moving memberplate towards one side of an optical axis direction of the lens and thatthe second support protrusion protrudes from the first moving memberplate towards another side of the optical axis direction, the firstguide recess of the first support mechanism is formed on the secondmoving member plate so as to be recessed toward the one side of theoptical axis direction, and the first guide recess has two side surfacesexpanding along the optical axis direction so as to oppose to eachother, and a bottom surface that connects the two side surfaces, thesecond guide recess of the second support mechanism is formed on thelens support so as to be recessed toward another side of the opticalaxis direction, and the second guide recess has two side surfacesexpanding along the optical axis direction so as to oppose to eachother, and an upper surface that connects the two side surfaces.
 2. Alens driving device according to claim 1, wherein the first supportprotrusion and the first guide recess are in contact each other at anends thereof in the optical axis direction, and the second supportprotrusion and the second guide recess are in contact each other at anends thereof in the optical axis direction.
 3. A lens driving deviceaccording to claim 1, wherein the first moving member plate and thesecond moving member plate are in contact only at the first supportprotrusion and the first guide recess.
 4. A lens driving deviceaccording to claims 1, wherein the lens support and the first movingmember plate are in contact only at the second support protrusion andthe second guide recess.
 5. A lens driving device according to claim 1,wherein the lens support is provided with a magnet that generates adriving force for movement, the second moving member plate is providedwith a magnetic member so as to generate an attraction force between themagnet and the magnetic member along the optical axis direction throughintermediation of the second moving member plate.
 6. A lens drivingdevice according to claim 1, wherein the second moving member plate hasa rectangular bottom plate having four corners, a protrusion thatprotrudes toward the optical axis direction is provided on each fourcorner of the rectangular bottom plate, a cover is fixed to a distal endof the protrusion, and a gap is formed between the cover and the lenssupport in the optical axis direction.
 7. A lens driving deviceaccording to claim 1, wherein the first support mechanism and the secondsupport mechanism are provided on each corner of rectangular outerprofiles of the lens support, the first moving member plate, and thesecond moving member plate when viewing from the optical axis direction,and the first support mechanism and the second support mechanism areoverlaid each other at each corner of the rectangular outer profiles. 8.A lens driving device according to claim 1, wherein the first supportprotrusion is in contact with the two side surfaces and the bottomsurface of the first guide recess, and the second support protrusion isin contact with the side surfaces of the upper surface of the secondguide recess.
 9. A lens driving device according to claim 2, wherein thefirst support mechanism and the second support mechanism are provided oneach corner of rectangular outer profiles of the lens support, the firstmoving member plate, and the second moving member plate when viewingfrom the optical axis direction, and the first support mechanism and thesecond support mechanism are overlaid each other at each corner of therectangular outer profiles.
 10. A lens driving device according to claim3, wherein the first support mechanism and the second support mechanismare provided on each corner of rectangular outer profiles of the lenssupport, the first moving member plate, and the second moving memberplate when viewing from the optical axis direction, and the firstsupport mechanism and the second support mechanism are overlaid eachother at each corner of the rectangular outer profiles.
 11. A lensdriving: device according to claim 4, wherein the first supportmechanism and the second support mechanism are provided on each cornerof rectangular outer profiles of the lens support, the first movingmember plate, and the second moving member plate when viewing from theoptical axis direction, and the first support mechanism and the secondsupport mechanism are overlaid each other at each corner of therectangular outer profiles.
 12. A lens driving device according to claim5, wherein the first support mechanism and the second support mechanismare provided on each corner of rectangular outer profiles of the lenssupport, the first moving member plate, and the second moving memberplate when viewing from the optical axis direction, and the firstsupport mechanism and the second support mechanism are overlaid eachother at each corner of the rectangular outer profiles.
 13. A lensdriving device according to claim 6, wherein the first support mechanismand the second support mechanism are provided on each corner ofrectangular outer profiles of the lens support, the first moving memberplate, and the second moving member plate when viewing from the opticalaxis direction, and the first support mechanism and the second supportmechanism are overlaid each other at each corner of the rectangularouter profiles.
 14. A lens driving device according to claim 2, whereinthe first support protrusion is in contact with the two side surfacesand the bottom surface of the first guide recess, and the second supportprotrusion is in contact with the side surfaces of the upper surface ofthe second guide recess.
 15. A lens driving device according to claim 3,wherein the first support protrusion is in contact with the two sidesurfaces and the bottom surface of the first guide recess, and thesecond support protrusion is in contact with the side surfaces of theupper surface of the second guide recess.
 16. A lens driving deviceaccording to claim 4, wherein the first support protrusion is in contactwith the two side surfaces and the bottom surface of the first guiderecess, and the second support protrusion is in contact with the sidesurfaces of the upper surface of the second guide recess.
 17. A lensdriving device according to claim 5, wherein the first supportprotrusion is in contact with the two side surfaces and the bottomsurface of the first guide recess, and the second support protrusion isin contact with the side surfaces of the upper surface of the secondguide recess.
 18. A lens driving device according to claim 6, whereinthe first support protrusion is in contact with the two side surfacesand the bottom surface of the first guide recess, and the second supportprotrusion is in contact with the side surfaces of the upper surface ofthe second guide recess.
 19. A lens driving device according to claim 7,wherein the first support protrusion is in contact with the two sidesurfaces and the bottom surface of the first guide recess, and thesecond support protrusion is in contact with the side surfaces of theupper surface of the second guide recess.
 20. A camera device,comprising: the lens driving device of claim 1; and a lens supported bythe lens support.
 21. An electronic apparatus, comprising the cameradevice of claim 19.